Object holder

Abstract

There is provided an object holder configured to support an object used in an exposure apparatus for a semiconductor manufacturing process, comprising a plurality of support elements defining a support surface and comprising at least two layers; wherein a first layer is a substoichiometric chromium based layer or a metal-Si multilayer or metal-Ge multilayer, configured to provide a selectively changeable height of individual support elements via thermal treatment of the first layer; wherein a second layer is more compressively stressed than the first layer, and located closer to a free end of the support element, wherein a layer thickness of said first layer of at least some of the support elements has been reduced via thermal laser treatment. Also described is an optical element for an exposure apparatus, an exposure apparatus, and a method of correcting the flatness of a surface of an object holder or optical element.

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